## **Learning Outcomes**

This article explains how intentional tort doctrines protect public interests through necessity and public authority privileges, giving you a focused framework for tackling MBE questions in this area. It clarifies the elements, scope, and policy behind the defense of public necessity, contrasting it with private necessity and emphasizing how absolute and qualified privileges differently allocate loss for property damage. It explains how public authority privileges shield officials and others acting under lawful authority when they reasonably interfere with private rights to prevent public harm or enforce the law. The article details the requirements of reasonableness, proportionality, temporal urgency, and proper targeting that constrain these doctrines, and highlights when overreaching conduct falls outside any privilege. It connects these defenses to specific intentional torts—especially trespass to land, trespass to chattels, conversion, nuisance, battery, and false imprisonment—and shows how necessity and official authority interact with other defenses such as self-defense and defense of others. Finally, it trains you to spot typical MBE fact patterns, avoid common traps, and choose between public necessity, private necessity, public authority privilege, or no privilege at all.

## **MBE Syllabus**

For the MBE, you are required to understand how intentional torts interact with the protection of public interests, with a focus on the following syllabus points:

- Identifying when the defense of public necessity applies to intentional torts.
- Distinguishing between public and private necessity.
- Recognizing the scope of privileges for public officials and those acting under legal authority.
- Understanding the limits of individual rights when weighed against the welfare or safety of the public.
- Applying these doctrines to scenarios involving trespass, conversion, and other intentional torts.
- Relating necessity and public authority privileges to other defenses (self-defense, defense of property, consent).

## **Test Your Knowledge**

_Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision._

1. A fire chief orders a house to be demolished to prevent a wildfire from spreading to the town. The owner sues for trespass. What is the best defense?  
   a) Private necessity  
   b) Consent  
   c) Public necessity  
   d) Mistake

2. During a riot, a police officer damages a shop window while dispersing the crowd. The shopkeeper sues for trespass to land. Which is most likely to apply?  
   a) The officer is strictly liable.  
   b) The officer may claim privilege if acting lawfully.  
   c) The officer must pay damages.  
   d) The officer can only claim necessity if the shopkeeper consents.

3. A person destroys a neighbor’s fence to create a firebreak and save the entire village from a spreading fire. What is the likely result?  
   a) The person is liable for all damages.  
   b) The person is not liable if acting under public necessity.  
   c) The person is liable unless the neighbor is compensated.  
   d) The person is liable for punitive damages.

## **Introduction**

Intentional tort law ordinarily protects strong individual rights: to exclusive possession of land, to control over personal property, and to bodily integrity. Yet in rare situations, strict enforcement of those rights would seriously endanger the community. The common law therefore recognizes a small set of _privileges_ and _defenses_ that allow intentional interferences with private rights when necessary to avert greater public harms or to carry out public duties.

These doctrines are heavily policy-driven. They reflect the idea—also seen in criminal law’s necessity defense—that it is sometimes acceptable, even desirable, to choose the lesser of two evils to prevent a catastrophe. On the MBE, they appear most often in trespass, conversion, and nuisance questions, and in problems involving police or fire officials.

### Public Necessity

The defense of public necessity allows a person to intentionally interfere with another’s property or rights to prevent a significant threat to the public at large. This defense is _absolute_: if its requirements are met, the defendant is not liable even for actual property damage.

> **Key Term: Public Necessity**  
> A complete defense to intentional torts where the defendant reasonably believes that interfering with private property is necessary to avert a serious, imminent threat to the public or a large group, such as a fire, flood, epidemic, or large-scale riot.

Key features that the MBE expects you to spot:

- **Protected interest:** “The public” means the community or a large number of people, not just a few specific individuals.
- **Threat level:** Harm must be serious and imminent or apparently imminent (e.g., a rapidly spreading wildfire, a collapsing dam).
- **Reasonable belief:** The defendant need not be correct; it is enough that a reasonable person in the circumstances would believe the action was necessary.
- **Scope of privilege:** Typically applies to _property_ torts (trespass to land, trespass to chattels, conversion), not to intentional personal injuries. Using deadly force is analyzed under self-defense, not public necessity.
- **No duty to pay damages:** Because the privilege is absolute, the property owner bears the loss as part of the community’s shared risk.

Public necessity is often invoked by public officials (firefighters, police) but is not limited to them. A private citizen who reasonably acts to prevent a public disaster may also claim it.

### Private Necessity vs. Public Necessity

It is essential to distinguish public necessity from private necessity. Both reflect the lesser-of-two-evils idea, but they differ sharply in who is protected and what happens with damages.

> **Key Term: Private Necessity**  
> A qualified defense to intentional property torts where the defendant reasonably interferes with another’s property to protect a limited number of persons (often the defendant) or their property interests, but must pay for any actual harm caused.

Under **private necessity**:

- The defendant is _privileged to enter or use_ another’s land or property, so is _not_ liable for nominal or punitive damages for trespass.
- However, the defendant is liable for **actual damage** caused while exercising the privilege (e.g., breaking a dock while mooring a boat in a storm).

By contrast, under **public necessity**:

- The defendant is not liable even for actual damage, so long as the interference is reasonably necessary to protect the public.

> **Key Term: Absolute Privilege**  
> A legal immunity that completely bars liability for certain acts, such as those done under public necessity or by public officials acting within their lawful authority to protect public interests.

On the MBE, public necessity and certain public authority privileges are treated as **absolute** privileges, whereas private necessity creates only a **qualified** privilege.

### Authority of Public Officials

Public officials—police officers, firefighters, health inspectors, and other government agents—are often required to interfere with private interests to protect public safety or enforce the law. Tort doctrine gives them a **public authority privilege** when they act lawfully and reasonably.

> **Key Term: Public Authority Privilege**  
> A defense available to officials and others acting under legal authority, shielding them from liability for intentional torts committed while reasonably performing their public duties within the scope of lawful authority.

Examples include:

- Entering land with a valid warrant to search or seize property.
- Arresting a suspect with probable cause, even if it turns out the suspect is innocent.
- Destroying property that is itself dangerous (e.g., diseased livestock, illegal weapons).
- Establishing cordons or barriers that temporarily block access to private premises during emergencies.

Important limitations:

- The official must be acting **within the scope** of legal authority (statutes, regulations, or common-law powers).
- The conduct must be **reasonable in manner and extent**—no more force or damage than necessary.
- If the official acts in **bad faith**, knows they lack authority, or goes far beyond that authority, the privilege may not apply.

These privileges sometimes overlap with public necessity. A fire chief who orders demolition of buildings to create a firebreak, for example, may invoke both the official authority granted by statute and the common-law privilege of public necessity.

### Limits and Requirements

The protection of public interests does not grant a blank check. The doctrine is narrowly confined to situations where immediate public harm is threatened.

Requirements common to public necessity and public authority privileges:

- **Reasonableness:** The actor’s belief in the necessity of the interference must be objectively reasonable under the circumstances.
- **Proportionality:** The degree of interference (e.g., level of force, extent of property damage) must be proportionate to the threat.
- **Temporal connection:** The action must be taken when the danger is imminent or ongoing, not after the fact.
- **Proper target:** The act must be directed at preventing or mitigating the danger, not at punishing individuals or gaining unrelated advantages.

If the actor exceeds what is reasonably required—e.g., a police officer uses deadly force against a non-dangerous suspect, or an official destroys property unrelated to the emergency—the privilege will not extend to the excessive portion.

### How These Doctrines Interact With Specific Torts

On the MBE, these defenses often arise in the context of:

- **Trespass to land:** Entering land without permission; necessity may justify entry.
- **Trespass to chattels / conversion:** Interfering with or destroying personal property; necessity may justify seizing or destroying dangerous items.
- **Nuisance:** Abating a public nuisance can be privileged when done by officials or private parties authorized to protect the public.
- **Battery and false imprisonment:** Public authority privileges (e.g., lawful arrest with proper force) may shield officers from liability when they physically restrain individuals.

Remember: **necessity defenses are strongest for property torts.** When bodily harm is involved, courts are much more cautious, and self-defense or defense of others usually provides the framework.

### **Worked Example 1.1**

A city orders the destruction of a warehouse to create a firebreak and stop a rapidly spreading fire threatening the entire city. The warehouse owner sues for trespass and conversion.

> **Answer:**  
> The city can rely on the defense of public necessity. The destruction was reasonably necessary to prevent a disaster affecting the public. This is an absolute privilege: the city is not liable for trespass or for the value of the warehouse.

### **Worked Example 1.2**

During a chemical spill, a police officer enters private homes without a warrant to evacuate residents and prevent mass poisoning. The homeowners sue for trespass.

> **Answer:**  
> The officer is protected by public authority privilege. Entering the homes was necessary to protect public health, and the officer acted lawfully and reasonably in scope and manner, so no liability for trespass arises.

### **Worked Example 1.3**

A hiker, to save herself from a sudden flood, breaks into a private cabin and causes minor damage. The owner sues for trespass and property damage.

> **Answer:**  
> The hiker may claim private necessity. She is privileged to enter to protect herself from imminent harm, so she is not liable for the mere trespass, but she must pay for the actual damage caused to the cabin.

### **Worked Example 1.4**

Thinking a wildfire is about to engulf the town, a volunteer uses a private bulldozer to knock down several fences and sheds to create a firebreak. The wind shifts, and the fire never reaches that area. The owners sue for trespass and conversion.

> **Answer:**  
> The volunteer can invoke public necessity if a reasonable person would have believed the fire threatened the town and that the destruction was necessary to protect the public. The defense does not require that the danger actually materialize. If the belief and the response were reasonable, the privilege is absolute and there is no liability for the destroyed property.

### **Worked Example 1.5**

A boat owner is caught in a severe storm and moors to a private dock without permission, damaging the dock but preventing his passengers (a small group of friends) from likely drowning. The dock owner sues.

> **Answer:**  
> This is private, not public, necessity. The boat owner had a qualified privilege to use the dock to protect the small group, so he is not liable for trespass, but must pay the dock owner for the actual damage to the dock.

### **Worked Example 1.6**

Police obtain a valid warrant to search House A. Due to a clerical error, the address is typed incorrectly, and they force entry into House B, damaging the door. They quickly realize the mistake and leave. The owner of House B sues for trespass and property damage.

> **Answer:**  
> The officers can claim a public authority privilege only if their entry was reasonable under the warrant. Once it becomes clear that the warrant does not apply to House B, the privilege ends. The initial forced entry based on a reasonable mistake is often privileged, but remaining or causing additional damage after the error is obvious may be unreasonable. Expect the MBE to test that the privilege covers reasonable execution of a warrant, including reasonable mistakes, but not clearly unjustified conduct.

### Exam Warning

> The defense of public necessity is absolute only when the act is taken to protect the public at large or a substantial number of people. If the act primarily benefits only one person or a small, identifiable group (even in an emergency), the defense is private necessity, and the actor remains liable for actual damages.

### Additional Exam Warning

> Do not automatically assume that any action by police or firefighters is privileged. On the MBE, you must check: (1) was there lawful authority (warrant, statute, or common-law power)? and (2) was the manner of execution reasonable and proportionate? If not, intentional tort liability remains possible.

### Revision Tip

> On the MBE, always ask two questions in property-interference scenarios:
>
> 1. Was the act done to protect the public or only private interests?
> 2. Was the actor a public official acting under lawful authority, or a private party?  
>    These questions determine whether the defense is public necessity (absolute), private necessity (qualified), public authority privilege, or no privilege at all.

## **Key Point Checklist**

_This article has covered the following key knowledge points:_

- Public necessity is a complete defense to intentional property torts when the defendant reasonably believes that interfering with private property is necessary to protect the public from serious, imminent harm.
- Private necessity is a limited defense; it creates a privilege to enter or use another’s property to protect a limited group or private interest, but the actor must pay for any actual damage caused.
- Public officials have privileges when acting lawfully, within the scope of their authority, and reasonably to protect public interests, including entering land, seizing property, or using reasonable force.
- These privileges are constrained by reasonableness and proportionality; excessive or bad-faith conduct falls outside the privilege and can generate tort liability.
- Necessity and public authority privileges interact primarily with property torts; when bodily harm is involved, self-defense and defense of others usually provide the governing framework.

## **Key Terms and Concepts**

- Public Necessity
- Private Necessity
- Absolute Privilege
- Public Authority Privilege

Intentional torts - Protection of public interests